Ornithobacteriosis in poultry

Ornithobacteriosis (ORT) is a recently described respiratory disease of tur keys and chickens. The etiologic agent of ORT is Ornithobacterium rhinotrac helae, Gram-negative, rod-shaped bacterium, initially identified in 1994. I nvestigations of isolates from turkeys and chickens revealed a probable wor ldwide distribution of this bacterium. In Poland the first cases were diagn osed towards the end of 1995. ORT attacks young and older birds, especially breeders. Clinical signs resemble fowl cholera, but with a lower mortality rate. Due to acquired resistance, treatment is sometimes difficult. Invest igations with vaccines in chickens and turkeys are promising, but due to se rotypical differentiations (currently 12 serotypes have been described) the re is no commercially available vaccine yet.